1. Field of the Invention
The present invention generally relates to an image detecting method, an image detecting system, a program and a recording medium for rendering image detection, and, in particular, to an image detecting method, an image detecting system, a program and a recording medium for rendering image detection for detecting a semicircular image having a specific size.
2. Description of the Related Art
Recently, a technology in that a seal (having a circular outline in many cases) or the like printed on a document is identified automatically from an electronic image thereof is demanded. As such a technology, Japanese Laid-Open Patent No. 8-115022 discloses a method of detecting a circle included in an electronic image. In this method, continuity of the midpoints between edges of a circle are determined, and, thus, a specific circle is detected.
However, in such a method, in a case where edges of a circle are partially faint or have discontinuity, or positions of the edges are shifted due to various noises, continuity of the midpoints between the edges is not secured. Thereby, detection of the circle may not be performed successfully. Thus, this method is not robust against distortion of an image to be processed.